kidney function 1 Flashcards
what does sodium transport facilitate
reabsorption of water, ions and nutrients
what type of cells line the proximal convoluted tubule
simple epithelium with microvilli for optimal reabsorption
what capillaries run alongside the proximal convoluted tubule
peritubular capillaries
what is not reabsorbed into the blood
creatinine
what method of transport is used by molecules moving from the PCT to the blood
passive diffusion, glomerular filtration has left a very low conc of nutrients in the blood remaning they can flow from a high conc to a low conc
how does water move from the PCT to the blood
via aquaporins
how do glucose and amino acids move from the PCT to the blood
via sodium co transporters
How does the Na/K pump ensure all molecules can be rebsorbed
pumps sodium against its concentration gradient and..
water always follows sodium
glucose and amino acids are co transported with sodium
negative ions follow the electrical gradient
what sections of the loop of henle contain aquaporins
the thin descending limb
what section of the loop of henle is the site of sodium reabsorption
thick ascending limb
how is sodium reabsorbed in the loop of henle
via NKCC2
counter current multiplication
reabsorbs water and concentrates urine
1 - thick ascending limb pumps Na+ out making interstitial salty
2 - water coming from PCT leaves the thin descending limb to balance gradient and reach equilibrium
- continuous cycle -
what regulates the rate of Na+ and H2O reabsorption in the distal convoluted tubule
hormones
what influence does ADH (vasopressin) have on the DCT
sees insertion of aquaporins allowing H2O to be reabsorbed from the filtrate
what influence does aldosterone have on the DCT
works alongside ADH and upregulates the insertion of Na/K pumps meaning more Na is reabsorbed and therefore more water also
